Proteome analysis of spinal cord during the clinical course of monophasic experimental autoimmune encephalomyelitis

The induction of autoimmune encephalomyelitis (EAE) in Lewis rats results in a period of exacerbation followed by complete recovery. Therefore, this model is widely used for studying the evolution of multiple sclerosis. In the present investigation, differentially expressed proteins in the spinal cord of Lewis rats during the evolution of EAE were assessed using the combination of 2DE and MALDI-TOF MS. The majority of the differentially expressed proteins were identified during the acute phase of EAE, in relation to naive control animals. On the other hand, recovered rats presented a similar protein expression pattern in comparison with the naive ones. This observation can be explained, at least in part, by the intense catabolism existent in acute phase due to nervous tissue damage. In recovered rats, we have described the upregulation of proteins that are apparently involved in the recovery of damaged tissue, such as light and medium neurofilaments, glial fibrillary acidic protein, tubulins subunits, and quaking protein. These proteins are involved mainly in cell growth, myelination, and remyelination as well as in astrocyte and oligodendrocyte maturation. The present study has demonstrated that the inflammatory response, characterized by an increase of the proliferative response and infiltration of autoreactive T lymphocytes in the central nervous system, occurs simultaneously with neurodegeneration.

The protein LJM 111 from Lutzomyia longipalpis Salivary Gland Extract (SGE) accounts for the SGE-inhibitory effects upon inflammatory parameters in experimental arthritis model

Several studies have pointed out the immunomodulatory properties of the Salivary Gland Extract (SGE) from Lutzomyia longipalpis. We aimed to identify the SGE component (s) responsible for its effect on ovalbumin (OVA)-induced neutrophil migration (NM) and to evaluate the effect of SGE and components in the antigen-induced arthritis (AIA) model. We tested the anti-arthritic activities of SGE and the recombinant LJM111 salivary protein (rLJM111) by measuring the mechanical hypernociception and the NM into synovial cavity. Furthermore, we measured IL-17, TNF-alpha and IFN-gamma released by lymph nodes cells stimulated with mBSA or anti-CD3 using enzyme-linked immunosorbent assay (ELISA). Additionally, we tested the effect of SGE and rLJM111 on co-stimulatory molecules expression (MHC-II and CD-86) by flow cytometry. TNF-alpha and IL-10 production (ELISA) of bone marrow-derived dendritic cells (BMDCs) stimulated with LPS, chemotaxis and actin polymerization from neutrophils. Besides, the effect of SGE on CXCR2 and GRK-2 expression on neutrophils was investigated. We identified one plasmid expressing the protein LJM111 that prevented NM in OVA-challenged immunized mice. Furthermore, both SGE and rLJM111 inhibited NM and pain sensitivity in AIA and reduced IL-17, TNF-alpha and IFN-gamma. SGE and rLJM111 also reduced MHC-II and CD-86 expression and TNF-alpha whereas increased IL-10 release by LPS-stimulated BMDCs. SGE, but not LJM 111, inhibited neutrophils chemotaxis and actin polymerization. Additionally, SGE reduced neutrophil CXCR2 expression and increased GRK-2. Thus, rLJM111 is partially responsible for SGE mechanisms by diminishing DC function and maturation but not chemoattraction of neutrophils. (C) 2012 Elsevier B.V. All rights reserved.

Immune Regulatory Properties of Allogeneic Adipose-Derived Mesenchymal Stem Cells in the Treatment of Experimental Autoimmune Diabetes

Adipose-derived mesenchymal stem cells (ADMSCs) display immunosuppressive properties, suggesting a promising therapeutic application in several autoimmune diseases, but their role in type 1 diabetes (T1D) remains largely unexplored. The aim of this study was to investigate the immune regulatory properties of allogeneic ADMSC therapy in T cell-mediated autoimmune diabetes in NOD mice. ADMSC treatment reversed the hyperglycemia of early-onset diabetes in 78% of diabetic NOD mice, and this effect was associated with higher serum insulin, amylin, and glucagon-like peptide 1 levels compared with untreated controls. This improved outcome was associated with downregulation of the CD4(+) Th1-biased immune response and expansion of regulatory T cells (Tregs) in the pancreatic lymph nodes. Within the pancreas, inflammatory cell infiltration and interferon-gamma levels were reduced, while insulin, pancreatic duodenal homeobox-1, and active transforming growth factor-beta 1 expression were increased. In vitro, ADMSCs induced the expansion/proliferation of Tregs in a cell contact-dependent manner mediated by programmed death ligand 1. In summary, ADMSC therapy efficiently ameliorates autoimmune diabetes pathogenesis in diabetic NOD mice by attenuating the Th1 immune response concomitant with the expansion/proliferation of Tregs, thereby contributing to the maintenance of functional beta-cells. Thus, this study may provide a new perspective for the development of ADMSC-based cellular therapies for T1D. Diabetes 61:2534-2545, 2012

Experimental models of autoimmune inflammatory ocular diseases

Ocular inflammation is one of the leading causes of blindness and loss of vision. Human uveitis is a complex and heterogeneous group of diseases characterized by inflammation of intraocular tissues. The eye may be the only organ involved, or uveitis may be part of a systemic disease. A significant number of cases are of unknown etiology and are labeled idiopathic. Animal models have been developed to the study of the physiopathogenesis of autoimmune uveitis due to the difficulty in obtaining human eye inflamed tissues for experiments. Most of those models are induced by injection of specific photoreceptors proteins (e.g., S-antigen, interphotoreceptor retinoid-binding protein, rhodopsin, recoverin, phosducin). Non-retinal antigens, including melanin-associated proteins and myelin basic protein, are also good inducers of uveitis in animals. Understanding the basic mechanisms and pathogenesis of autoimmune ocular diseases are essential for the development of new treatment approaches and therapeutic agents. The present review describes the main experimental models of autoimmune ocular inflammatory diseases.

Leukotrienes Are Upregulated and Associated with Human T-Lymphotropic Virus Type 1 (HTLV-1)-Associated Neuroinflammatory Disease

Leukotrienes (LTs) are lipid mediators involved in several inflammatory disorders. We investigated the LT pathway in human T-lymphotropic virus type 1 (HTLV-1) infection by evaluating LT levels in HTLV-1-infected patients classified according to the clinical status as asymptomatic carriers (HACs) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients. Bioactive LTB4 and CysLTs were both increased in the plasma and in the supernatant of peripheral blood mononuclear cell cultures of HTLV-1-infected when compared to non-infected. Interestingly, CysLT concentrations were increased in HAM/TSP patients. Also, the concentration of plasma LTB4 and LTC4 positively correlated with the HTLV-1 proviral load in HTLV-1-infected individuals. The gene expression levels of LT receptors were differentially modulated in CD4(+) and CD8(+) T cells of HTLV-1-infected patients. Analysis of the overall plasma signature of immune mediators demonstrated that LT and chemokine amounts were elevated during HTLV-1 infection. Importantly, in addition to CysLTs, IP-10 was also identified as a biomarker for HAM/TSP activity. These data suggest that LTs are likely to be associated with HTLV-1 infection and HAM/TSP development, suggesting their putative use for clinical monitoring.

Human Endometrial-Derived Mesenchymal Stem Cells Suppress Inflammation in the Central Nervous System of EAE Mice

FAPESP [2009/13109-5]

Exploring the Role of Soluble Factors Associated with Immune Regulatory Properties of Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are characterized as multipotent stromal cells with the capacity for both self-renewal and differentiation into mesodermal cell lineages. MSCs also have a fibroblast-like phenotype and can be isolated from several tissues. In recent years, researchers have found that MSCs secrete several soluble factors that exert immunosuppressive effects by modulating both innate (macrophages, dendritic and NK cells) and adaptive (B cells and CD4+ and CD8+ T cells) immune responses. This review summarizes the principal trophic factors that are related to immune regulation and secreted by MSCs under both autoimmune and inflammatory conditions. The understanding of mechanisms that regulate immunity in MSCs field is important for their future use as a novel cellular-based immunotherapy with clinical applications in several diseases.

Organ-specific autoantibodies and autoimmune diseases in juvenile systemic lupus erythematosus and juvenile dermatomyositis patients

Objectives To our knowledge, no study assessed simultaneously a variety of organ-specific autoantibodies and the prevalence of organ-specific autoimmune diseases in juvenile systemic lupus erythematosus (ISLE) and juvenile dermatomyositis (JDM). Therefore, the purpose of this study was to evaluate organ-specific autoantibodies and autoimmune diseases in JSLE and JDM patients. Methods Forty-one JSLE and 41 JDM patients were investigated for autoantibodies associated with autoimmune hepatitis, primary biliary cirrhosis, type I diabetes mellitus (TIDM, autoimmune thyroiditis (AT), autoimmune gastritis and coeliac disease (CD). Patients with positive antibodies were investigated for the respective organ-specific autoimmune diseases. Results Mean age at diagnosis was higher in ISLE compared to JDM patients (10.3 +/- 3.4 vs. 7.3 +/- 3.1 years, p=0.0001). The frequencies of organ-specific autoantibodies were similar in JSLE and JDM patients (p>0.05). Of note, a high prevalence of TIDM and AT autoantibodies was observed in both groups (20% vs. 15%, p=0.77 and 24% vs. 15%, p=0.41; respectively). Higher frequencies of ANA (93% vs. 59%, p=0.0006), anti-dsDNA (61% vs. 2%, p<0.0001), anti-Ro, anti-Sm, anti-RNP, anti-La and IgG-aCL were observed in JSLE (p<0.05). Organ-specific autoimmune diseases were evidenced only in ISLE patients (24% vs. 0%, p=0.13). Two ISLE patients had TIDM associated with Hashimoto thyroiditis and another had subclinical thyroiditis. Another JSLE patient had CD diagnosis based on iron deficiency anaemia, anti-endomysial antibody, duodenal biopsy compatible to CD and response to a gluten-free diet. Conclusions Organ-specific diseases were observed solely in ISLE patients and required specific therapy. The presence of these antibodies recommends the evaluation of organ-specific diseases and a rigorous follow-up.